NEMATODA, THREAD-WORMS 546 



were designated by Bavay as anguillula stercoralis. Another parasite soon 

 afterward found by Normand in patients of this kind was described by Bavay 

 as anguillula intestinalis. By the investigations of Leuckart, Grassi, and 

 Leichtenstern, the relations of these parasites have been determined with cer- 

 tainty. For purposes of study, I may refer to the investigations of the 

 previously mentioned authors as well as to those of Askanazy and Zinn. 



According to these investigations the development occurs in the following 

 manner: the hermaphroditic mother animal of the anguillula intestinalis, 

 according to Askanazy, lodges in the intestinal wall, chiefly in the mucous 

 membrane, and frequently bores its way into the epithelium of the gland, 

 there to take up nutritive products. The females at the same time deposit 

 their eggs here. The ova are transformed into embryos which then enter 

 the intestinal cavity. These are met with in fresh feces, often in great num- 

 bers, and, according to Zinn, in about twelve hours are transformed into filaria- 

 like larvae. These again enter the intestinal canal of man, and are here 

 formed into parasitic anguillula. This process is called direct metamorphosis. 



Other embryos of anguillula intestinalis develop outside the body in about 

 two to three days into sexually ripe male and female animals (rhabditis ster- 

 coralis). The direct descendants of these are the embryos of the rhabditis 

 stercoralis, from which the filaria-like larvae are again formed. The latter 

 wander into the intestinal canal of man, and grow into mother animals of the 

 parasitic anguillula intestinalis. This mode of development is designated by 

 Leuckart as heterogeny. This heterogeny, as was first emphasized by Leich- 

 tenstern, does not occur in the majority of cases, particularly in those of 

 European origin. 



Anguilluliasis occurs not only in southeastern Asia, Martinique and Bra- 

 zil, but was met with in 1878 and 1879 by Grassi and Parona in Italy, simul- 

 taneously with anchylostomiasis. Lately Askanazy found them in a game- 

 keeper in East Prussia who had never left his home, and who never came 

 in contact with Ehenish brickmakers. 



The parasites live in the Juices of the small intestines. Askanazy also 

 found them in the tissues of the mucosa, sometimes stretched out or rolled 

 together. They distribute themselves in the muscularis mucosa, and are met 

 with in great numbers in the region of Lieberkidm's glands. The parasite 

 enters the walls of the intestines to partake of the chyle. Here, according 

 to Askanazy, the eggs are deposited, and the parasite goes through its stages 

 of development. Teissier has observed that the embryos occasionally enter the 

 circulation. Askanazy seems to favor the view that the parasites are to be 

 regarded as no more than simple commensals. 



Of special interest is the: 



Filaria medinensis Velsch, 1674. 



The females attain a length of from 60 to 80 cm. and in form and appear- 

 ance resemble a catgut string. The male, according to Charles, has also 

 recently been found. It is only 4 cm. in length. Dracontiasis, as the path- 

 ologic phenomena produced by the parasite were called by Galen, is due to 

 the fact that the worm penetrates the human organism, and may remain for 

 36 



